Driving mechanism



July 20, 1948. H. M. STEPHENSON r 2,445,590

, muvme uzcamxsu Filed July 8, 1944 V 2 Sheets-Sheet 1 Inventor'- HisAttorney- Hucgh M Stephenson, I

y 1948. H. M. STEPHENSON 2,445,590

DRIVING MECHANISM Filed July 8, 1944 2 sheetshana v v Inventor: Hughflstephenson,

l-hs Attorney.

Patented July 20, 1948 Hugh M. Stephenson: Fort to General ElectricCompany,

New York Wayne, Ind., assignor a corporation of Application .luly s.1944, Serial No. 544,069

13 Claims.

My invention relates to driving mechanism and particularly to anarrangement for releasing a driving connection on the occurrence of asudden deceleration of the mechanism.

An object of my invention is to provide an improved driving mechanismprovided with an inertia release arrangement for releasing the drivingconnection on sudden deceleration of the mechanism.

Another object of my invention is to provide an improved inertia releaseslip clutch.

Further objects and advantages of my invention will become apparent andmy invention will be better understood from the following descriptionreferring to the accompanying drawing, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming part of this specification.

In the drawing, view, partly broken away,

Fig. 1 is an end elevational showing an embodiment of my improveddriving mechanism with an inertia release drive; Fig. 2 is a sideelevational view, partly in section taken along line 2---2 of Fig. 1;Fig. 3 is a fragmentary sectional view taken along the direction of thearrow 3 in Fig. 2; Fig. 4 is an end view. partly broken away, Of anotherembodiment of my invention:

.Fig. 5 is a sectional elevational view taken along line 5-5 of Fig. 4;and.Fig. 6 is a fragmentary view taken along line G-6 of Fig. 5.

Referring to the drawing, I have shown in Figs. 1 to 3, inclusive, anembodiment of my improved driving mechanism which includes a pair ofdrive members comprising a driving member having a driving shaft I anddrum 2 secured thereto with a spring seat groove 3 on the outer flangethereof. Driving torque is adapted to be transmitted from the drivingshaft I to a driven member through an arcuate spring 4 having spacedapart ends and formed with a radial width which varies directly with thecircumferential distance from the midpoint circumferentially of thespring. This spring 4 is arranged under compression to a smallerdiameter than its released diameter in frictional engagement with thesurface-of the drum spring seat groove 3 to provide a frictionaldrivingconnection therewith. Each end of the spring is formed with aninwardly projecting driving part 5 which is adapted to engage a drivingprojecting part 6 formed on a drive plate 1 which is secured to a drivenshaft 8. Torqueis transmitted from the driving shaft I to the drivenshaft} by engagement of the spring driving end part i with one or theother of the drive plate parts 4, and

the end 9 of the driven shaft 8 is formed on a smaller diameter and isjournaled in a hollow section ID of the drivingshaft I to assist inmaintaining these two shafts in axial alignment. A thrust bearing II isarranged about the driving shaft I between the drive member drum 2andthe drive plate I.

In this type mechanism, a. sudden change in load or an overload mayoccur which may tend to stop or suddenly decelerate the mechanism, and arigid connection between the driving and driven members might causedestructive stresses to be set up therein. In order to prevent suchaction, an inertia release device is provided for releasing the drivingconnection between the driving member drum and the spring to release theconnection between the two drive members. This includes a spring releasepin I2 secured to each end '5 of the spring 4 which projects in adirection away from the driving member drum 2, and

' an inertia load release plate or flywheel member I3 rotatably mountedon the driven shaft 8 and held in axial position by a positioning ringI4 which is secured to the shaft 8 by a setscrew I5. A thrust bearing I6is mounted on the driven shaft 8 between the drive plate I and theinertia plate I3 in order to minimize the friction therebetween. Theplate I3 is formed with an open: ing I'l arranged about the springrelease pins I2 .and is formed with tapered cam end-side surfaces I8arranged for engagement with the spring release pins I2, such that whena sudden deceleration of the mechanism occurs, the inertia ofthe plateI3 tends to cause the plate to continue at its original speed, causingit to expend its inertia against the spring release pin I2 on theleading end of the spring, thus causing the spring to tend to wrap to asmaller diameter and relieving the driving friction between the springand the drum spring seat for releasing the driving connectiontherebetween. The spring size and the degree of compression of thespringcan,

be varied to provide any predetermined maximum torque to be transmittedby the driving mechanism, such that torque above this maximum value willcause slipping between the spring and the driving drum and prevent thetransmittalof destructive forces through the mechanism. In this manner,a. combined slip clutch and inertia release mechanism is provided forreleasing the connection when undesirablestresses might be set upif arigid connectionwere provided.

Referring to Figs. 4, 5 and 6 of the drawing, I have shown anotherembodiment of my improved driving mechanism which includes a drivin 3member and a driven memberhaving respectively a driving shaft and adriven shaft adapted to be coupled by a slip clutch. In thisconstruction, a driving shaft I9 is provided with a drum 20 having a hub2| for mounting the drum on the shaft l9, and the assembly is securedtonection between the shoe members and the drum 20. As in theconstruction shown in Figs. 1, 2

and 3, the size and the degree of compression of gether by a setscrew22. Driving torque is adapted to be transmitted from the driving shaftis to a driven member through a set of three arcuate springs 23 havingspaced apart ends and formed with a radial width which varies directlywith the circumferential distance from the midpoint circumferentially ofthe spring. A plurality of circumferentially spaced apart friction shoemembers 24 are arranged in the drum and extend into engagement with theouter periphery of the arcuate springs 23 which are held undercompression within the drum 20, in engagement with the inner surface ofthe friction shoe members for biasing these shoe members into frictionaldriving connection with the inner surface of the drum. Each of thesesprings is formed with a driving part 25 in the form of a head of a pin26 on each end of the spring, and these pinheads 25 are spaced a slightdistance from driving parts 21 which project outwardly on a drive plate28 secured to a driven shaft 29. Axial alignment of the two shafts ismaintained by forming the end portion 30 of the driving shaft 29 ofreduced diameter and Journaling it in abearing 3| mounted within the hub2| of the drum 20. The fraction shoe members 24 are held incircumferentially spaced apart relationship by an axially extendingflange 32 which is formed on the outer periphery of an inertia platemember 33 and which is provided with a plurality of openings 34 throughwhich the shoe members loosely extend to provide for free relativeradial movement of the shoe members. The inertia plate 33 is secured toa bearing hub 35 which is rotatably mounted on the drive shaft 29 and isformed with a circumferentially extending opening 36 which extends aboutends 31 of the pins 26 which are adapted to act as spring der certainoperating conditions.

In this construction, torque is adapted to be transmitted between thetwo drive members from the driving shaft IE! to the driven shaft 29through the frictional driving connection formed by the engagement ofthe friction shoe members with the drum 20 under the action ofcentrifugal force on the shoe. members augmented by the radialfrictional pressure engagement of the springs 23 wtih the inner surfacesof the shoe members 24 and the mechanical connection of the springsthrough the pinheads 25 and the driving parts 21 of the driveplate 28.If an overload or sudden stop is imposed on this driving mechanism suchthat there is a sudden deceleration of the mechanism, the inertia devicewill tend to release the pressure of the friction shoe members 24 on thedrum 20 and permit the clutch to slip, thereby preventing destructivestresses from being set up in the mechanism. This action is provided bythe inertia plate 33 which tends to continue to rotate at .its originalspeed such that an end of the opening 36 forms a mechanical connectionwith one of the pinheads 25 and tends to expend the inertia of the plateagainst the spring release pin 26 on the leading end of the springs 23,thus causing the springs to tend to wrap to a smaller diameter andrelieving the pressure of the spring on the shoe members for releasingthe driving conthe springs can be varied to provide any predeterminedmaximum torque to be transmitted by the driving mechanism, and thenumber of springs and size of the friction shoe members may also bevaried in accordance with the desired maximum torque to be transmittedby the mechanism. This arrangement is adapted to beheld in assembledrelationship by a closure plate 38 which is mounted on the outer end ofthe drum 20 and on a rotatably mounted ring 33 on the driven shaft 29.

While I have illustrated and described particular embodiments of myinvention, modifications thereof will occur to those skilled in the art.I desire it to' be understood, therefore, that my invention is not to belimited to the particular arrangements disclosed, and I intend in theappended claims to cover all modifications which do not depart from thespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a drum secured to saiddriving member, means including an arcuate spring having spaced apartends and formed with a radial width which varies inversely with thecircumferential distance from the midpoint circumferentialiy of thespring and arranged under compression in said drum for providing africtional driving connection with said drum, means including a. driveplate secured to said driven member arranged to apply force on saidspring for transmitting torque from said driving member to said drivenmember through said spring, means including an inertia load releasedevice comprising a plate member rotatably mounted on said driven memberand arranged for mechanical connection with said spring for biasing saidspring to a smaller diameter for releasing the driving connectiontherebetween on sudden deceleration of said mechanism.

2. A driving mechanism including a driving member having a drum securedthereto, an arcuate spring having spaced apart ends and arranged undercompression in said drum for providing a frictional driving connectionwith said drum, a driving part on each end of said spring, a drivenmember including a drive plate secured thereto, means including drivingparts on said drive plate arranged for engagement with said springdriving parts for transmitting torque from said driving member to saiddriven member through said spring, means including a spring release pinon each end of said spring and an inertia-load release device includinga plate rotatably mounted on said driven member and arranged forengagement with said spring release pins for biasing said spring to asmaller diameter and relieving the driving friction between said springand said drum for releasing the driving connection therebetween onsudden deceleration of said mechanism.

3. A driving mechanism including a driving member having a drum securedthereto, an armate spring having spaced apart ends and arranged undercompression in engagement with the inner surface of said drum, 9.driving part on each end of said spring, a driven member including a theinner surface of said on said drive plate arranged for engagement withsaid spring driving parts for transmitting torque tion between saidspring and said drum for releasing the driving connection therebetweenon sudden deceleration of said mechanism.

4. A driving mechanism including a pair of shafts adapted to be coupledby a slip clutch comprising a drum secured to one of said shafts. anarcuate spring having spaced apart ends and arranged under compressionin engagement with the inner surf-ace of said drum, a driving part oneach end of said spring, a drive plate secured to the other of saidshafts, means including driving parts on Said drive plate arranged forengagement with said spring driving parts for transmitting-torque fromone of said shafts to the other of said shafts through said spring,means including a spring release pin on each end of said spring and aninertia load release device including a plate rotatably mounted on oneof said shafts and arranged for engagement with said spring release pinsfor biasing said spring to a smaller diameter and relieving the drivingfriction between said spring and said drum for reans-.000

said spring release pins for biasing said spring to a smaller diameterand relieving the driving friction-between said spring and said drum forreleasing the driving connection therebetween on sudden deceleration ofsaid mechanism.

7. A driving mechanism including a driving member having a drum securedthereto with a spring seat groove therein. an arcuate spring havingspaced apart ends and formed with a radial width which varies inverselywith the circumferential distance from the midpoint circumferentially ofthe spring and arranged under compression in engagement with the surfaceof said drum spring seat groove. a driving part on each end ofsaidspring, a driven member including a drive plate secured thereto,means including driving parts on said drive plate arranged forengagement with said spring driving parts for transmitting torque fromsaid driving member to said driven member through said spring, meansincluding a spring release pin on eachend of said spring and an inertiaload release device including a plate rotatably mounted on said drivenmember and arranged for engagement with said spring release pins forbiasing said spring to a smaller diameter and relieving the drivingfriction beleasing the driving connection therebetween on suddendeceleration of said mechanism.

5. A driving mechanism including a driving member having a driving shaftand a'drum secured thereto, an arcuate spring having spaced apart endsand arranged under compression in said drum for providing a frictionaldriving connection with said drum, 9. driving part on each end of saidspring, a driven member including a driven shaft with a drive platesecured thereto, means including driving parts on said arranged forengagement with said spring driving parts for transmitting torque fromsaid driving member to said driven member through said spring, a springrelease pin on each end of said spring, and an inertia load releasemeans including a plate rotatably mounted on said driven shaft andprovided with an opening having tapered cam side surfaces arranged forengagement with said spring release pins for biasing said spring to asmaller diameter and relieving the driving friction between said springand said drum for releasing the driving connection therebetween 0nsudden deceleration of said mechanism.

6. A driving mechanism including a pair of members adapted to be coupledby a slip clutch comprising a drum secured' to one of said members, anarcuate spring having spaced apart ends and formed with a radial widthwhich varies inversely with the circumferential distance from themidpoint circumferentlally of the spring and arranged under compressionin engagement with drum, a driving part on each end of said spring, adrive plate secured to the other of said members, means includingdriving parts on said drive plate arranged for engagement with saidspringdriving transmitting torque from one of said members to the otherof said members through said spring. means including a spring releasepin on each end of said spring and an inertia load release deviceincluding a plate rotatably mounted on one of said members and arrangedfor engagement with tween said spring and said drum spring seat forreleasing the driving connection therebetween on sudden deceleration ofsaid mechanism.

8. A driving mechanism including a driving member having a driving shaftand a drum secured thereto with a spring s'eat groove therein, anarcuate spring having spaced apart ends and formed with a radial widthwhich varies inversely with the circumferential distance from themidpoint circumferentially of the spring and arranged under compressionin engagement with the surface of said drum spring seat groove, adriving projecting part on each end ofsaid spring, a driven memberincluding a driven shaft with a drive plate secured thereto arranged insaid drum within said spring, means including driving prodrive plate Aparts for jecting "parts on said drive plate arranged for engagementwith said spring driving projecting parts for transmitting torque fromsaid driving member to said driven member through said spring, a springrelease pin projecting from each end of said spring away from said drum,and in inertia load release means including a plate rotatably mounted onsaid driven shaft and provided with an opening having tapered cam sidesurfaces arranged for engagement with said spring release pins forbiasing said spring to'a smaller diameter and relieving the drivingfriction between said spring and said drum spring seat for releasing thedriving connection therebetween on sudden deceleration of saidmechanism,

' 9. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a drum secured to saiddriving member. means including friction shoe members and anarcuate'spring having spaced apart ends and arranged under compressionin engagement with the inner surface of said friction shoe members forbiasing said friction shoe members into frictional driving connectionwith said drum, means including a drive plate secured to said drivenmember arranged to apply force to said spring for transmitting torquefrom said driving member to said driven member through said spring,means including an inertia load release device including a plate memberrotatably mounted on said driven member and arranged for mechanicalconnection with said spring for biasing said sprin to a smaller diameterfor releasing thedriving connection between said 1 driving and drivenmembers on sudden deceleration of said mechanism.

10. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a drum secured to saiddriving member, means including friction shoe members and an arcuatespring having spaced apart ends and arranged under compression inengagement with the inner surface said friction shoe members for biasingsaid friction shoe members into frictional driving connection with saiddrum, means including a drive plate secured to said driven memberarranged to apply force to said spring for transmitting torque from saiddriving member to said driven member through said spring, meansincluding a spring release pin on each end of said spring and an inertiaload release device including a plate member rotatably mounted onsaiddriven member and arranged for engagement with said spring releasepins for biasing said spring to a smaller diameter for releasing thedriving connection between said driving and driven members on suddendeceleration of said mechanism.

11. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a drum secured to saiddriving member, means including friction shoe members and an arcuatespring having spaced apart ends and arranged under compression inengagement with the inner surface of said friction shoe members forbiasing said triotion shoe members into a frictional driving connectionwith said drum, a driving part on each end of said spring, a drive platesecured to said driven member, means including driving parts on saiddrive'plate arranged to apply force to said spring driving parts fortransmitting torque from said driving member to said driven memberthrough said spring, means including an inertia load release devicecomprising a plate member rotatably mounted on said driven member andarranged for mechanical connection with said spring for leasing thedriving connection between said driving and driven members on suddendeceleration of said mechanism.

12. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a drum secured to saiddriving member, means including circumferentially spaced apart frictionshoe members in said drum and an arcuate spring having spaced apart endsand arranged under compression in engagement with the inner surface ofsaid friction shoe members for biasing said friction shoe members into africtional driving connection with I said drum, a driving part on eachend of said spring, a drive plate secured to the said drive member,means including driving parts on said drive plate arranged formechanical connection with said spring driving parts for transmittingtorque from said driving member to said driven member through saidspring, means including a spring release pin on each end of said springand an inertia load release device including a plate member rotatablymounted on said driven member and arranged for engagement with saidspring release pins for biasing said spring to a smaller diameter toreleasing the driving connection between said riving and driven memberson sudden deceleration oi said mechanism, said inertia plate memberhaving an axially extending flange with guide openings therein throughwhich said shoe members iooselyextend.

13. A driving mechanism including a driving member and a driven memberadapted to be coupled by a slip clutch comprising a' drum secured tosaid driving member, means including friction shoe members and anarcuate spring having spaced apart ends and formed with a radial widthwhich varies directly with the circumferential distance from themidpoint circumferentially oi the spring and arranged under compressionin engagement with-the inner. surface of said friction shoe members for-biasing said friction shoe members into a frictionaldriving connectionwith said drum, a driving part on each end of said spring, a drive platesecured to said driven member, means including driving parts on saiddrive plate arranged for mechanical connection with said spring drivingparts for transmitting torque from said driving member to said drivenmember through said spring, means including a spring release pin on eachend of said spring and an inertia load release device including a platemember rotatably mounted on said driven member and arranged forengagement with said spring release pins for biasing said spring to asmaller diameter for releasing the driving connection between saiddriving and driven members on sudden decelerabiasing said spring to asmaller diameter for reof said mechanism HUGH M. STEPHENSON.

REFERENCES CITED The following references are of record in the file, ofthis patent:

UNITED STATES PATENTS Stephenson Oct. 2, 1945

